Hey all
I may have a slight problem i may not, im not entirely sure

The thing is, i have my onboard sound from my nforce 3 mobo connected to the back of my amp at cd/aux. Im using this cable at the mo...
http://ws3.richersounds.com/showbigp...ame=101369.jpg
The single connecter end goes into the back of the pc whilst the split end goes into the left & right speaker plugs at the back of the amp.
Is this the best cable to use to produce audio sound from my pc + should i invest in a decent sound card to, as i listen to a lot of music through my computer ?
many thanks